In a known gas circuit breaker, in order to effectively interrupt a large current by a small operating force, the gas circuit breaker includes: a heating chamber which enhances the pressure of insulating gas using the heat of an arc; and a pair of cylinder and piston (mechanical puffer) which enhances the pressure of insulating gas by reducing a volume by a mechanical operating force. The heating chamber is a space disposed so as to surround an arc chamber between a contact tulip and an opening and closing pin with an operating axis of the opening and closing pin as a center line, and the heating chamber communicates with the arc chamber by blowing slits. During an interruption operation, pressure in the heating chamber rises by heat which is radiated passing through the blowing slits from an arc generated between the contact tulip and the opening and closing pin. Furthermore, a material constituting the blowing slits becomes evaporation gas by the heat of the arc; and accordingly, a pressure rise in the heating chamber is enhanced. The pressure rise is assisted by the supply of the insulating gas, which is compressed by the piston operating simultaneously with a contact opening operation of the opening and closing pin, to the heating chamber through a blowing path.
For example, in a known circuit breaker disclosed in Patent Document 1, in the case of crossing a next current zero point after a high pressure is generated in a heating chamber, insulating gas in the heating chamber flows from blowing slits to a discharge port provided on the opposite side of a pressure chamber with respect to an arc chamber via the arc chamber and the pressure chamber; and at the same time, the insulating gas flows into other discharge chamber on the opening and closing pin side via the arc chamber. Accordingly, a gas flow inevitably intersects with an arc and gas ionized in an intersection range is sufficiently removed; and therefore, an arc is not generated after crossing the current zero point and arc extinguishing is completed.
Furthermore, for example, in a known gas circuit breaker disclosed in Patent Document 2, in order to absorb a slight amount of moisture contained in arc extinguishing gas in the gas circuit breaker and a gas molecule formed by decomposition by an arc, an adsorbent of a porous body is laid or stored at a path where interrupting gas moves or a portion where the interrupting gas remains.
Further, for example, in a gas circuit breaker disclosed in Patent Document 3, a hydrogen absorbing alloy member is disposed in a flow path from a mechanical puffer to an arc chamber; hydrogen gas is discharged from the hydrogen absorbing alloy member overheated by an arc during a contact opening operation and the arc is cooled; and after completion of the contact opening operation, the temperature of the hydrogen absorbing alloy member decreases and the hydrogen gas is recovered again.